Improvement in burglar-alarms



n. MERSEREAU. 'BURGLAR-ALARMQ Patented Feb. 6

NAPETERS. PHUTO-LITNOGRAPHER WASHINGTON D. O.

UNIT D STATES PATENT FFIGE.

DANIEL MERSEREAU, OF NEWARK, NEW JERSEY.

IMPROVEMENT IN BURGLAR-ALARMS.

Specification forming part of Letters Patent No. 187,034, dated February 6, 1877; application filed September 30, 1876. v

To all whom it may concern:

Be it known that I, DANIEL MERSEREAU,

of Newark, in the county of Essex and State vice, the side plate being removed. Fig. 2 is a bottom view of the same. Fig. 3 is adetail cross-section of the same, taken through the line a: m, Fig. 2.

Similar letters of reference indicate corresponding parts.

The object of this invention is ,to furnishan improved burglar-alarm for application to doors and windows, which shall be so constructed as to serve as a fastening to the door or window, and will act as an alarm, should an attempt be made to open the said door or window, and which may be conveniently carried in the pocket or in a traveling-bag.

The invention will first be described in connection with the drawing, and then pointed out in the claim.

A is the case, which is made in the general shape of a truncated wedge, or in any other desired shape, and to the larger end of which is secured the gong B. O is the mainspring, one end of which is secured to the bottom of the case A, and its other end is attached to the shaft D. Upon the shaft D is placed a gear-wheel, E, which is connected with said shaft D by a pawl and ratchet, so

that the shaft may be turned to wind up the spring 0 by a knob or key applied to its end, and so that the said shaft may carry the mechanism with it as it is turned by the uncoiling of the spring 0. The teeth of the gear-wheel E mesh into the teeth of the small cog-wheel F, attached to or connected with the escapement-wheel G or its shaft. His the escapement, which engages with the escapement-wheel G, and is attached to the shaft I. To the escapementshaft I is attached the handle J of the hammer K, which is placed within the mouth of the gong B, so as to strike the opposite sides of said gong alternately as it is vibrated.

As thus far described, the mechanism is the same as that of an ordinary burglar-alarm.

Upon the side edges of the bottom of the case A are formed downwardly-projecting flanges a to form a seat for the plate L. To the inner side of the plate L is attached, or upon it isformed, a stud, M, which passes through a longitudinal slot in the bottom of the case A, and serves as a limit to the movement of the said slide L. The slide L may be kept in place by a pin passed transversely through the stud M, upon the inner side of the bottom of the case A, or by any other suitable means. The stud M is so located upon the slide L that when the said slide is pushed forward into the position shown in Fig. 2 the inner end of the said stud M may strike against the lower arm of the escapement H, and thus lock. the mechanism. Upon the forward end of the slide L are formed points or teeth 1 and upon its rear end may also be formed teeth or points Z if desired. Upon the rear end of one or both the flanges a of the bottom of the case A are formed points or teeth 00 as shown. in Fig. 1.

In using the device the slide L is pushed forward, and the spring 0 is wound up. The teeth I are inserted in the floor or carpet in such a position that the case A may stand in an inclined position, with its upper end resting against the door, and the teeth a, are pressed into the said door sufficiently to keep the device in place. If, now, an attempt be made to open the door, the case A will be pressed downward upon the slide L, which withdraws the stud M from the escapement H, and allows the alarm mechanism to operate the hammer to sound an alarm, while at the same time the device prevents the door from being opened. -In the case of a window the device is connected with the upper and lower sashes in such a way that the movement of either sash may move the case A and slide L upon each other and sound the alarm, and at the same time prevent the sashes from being opened.

I am aware that it is not new to release an alarm-detent by opening a door; but in such cases the alarm ceases assoc'n as-the stud, M,.lpassing threugh said case, and holddoor. is closed, while mine will continue, thus ing the escapement until the case is pressed insuring the result for which the device is inby the door, substantially as shown and de-' tended. I scribed.

What I claim as new is- DANIEL MERSEREAU. In burglar-alarms, the case A, secured by Witnesses; bottom flanges t0, and movable on, a sup- JAMESTpGRAHAM, port, L, the latter being provided with a O. SEDG-WIOK. 

